Basics in Glaucoma Dr. Sharmila Glaucoma clinic. Glaucoma Glaucoma is an optic neuropathy with characteristic appearance of the optic disc and specific.

Basics in Glaucoma

Dr. SharmilaGlaucoma clinic

Glaucoma Glaucoma is an

optic neuropathy with characteristic appearance of the optic disc and specific pattern of visual field defects that is associated frequently but not invariably with raised IOP

POAG

Adult onset IOP > 21mm Hg Open Angles Glaucomatous nerve damage Visual field loss

Risk factors

Age > 65Black racePositive family historyMyopiaThin Corneas

Pathogenesis Increased resistance to aqueous

outflow Ischaemic Theory Mechanical theory

pathogenesisPathogenesis

Symptoms

Usually asymtomatic Rarely decreased visual

fields

Diagnosis of glaucoma

History taking Visual acuity and refractive state Tonometry Gonioscopy Ophthalmoscopy Perimetry

Tonometry Indentation tonometry-schiotz

tonometer Applanation tonometry

variable force-goldmann Tonopen

variable area- maklakov Non contact tonometer

Schiotz indentation Tonometry

Body –footplate-rests on the cornea

Plunger Weights-

5.5gm –permanently fixed.

additional weights-7.5g.10g,15g

Technique of schiotz tonometry

Anaesthetise cornea Patient in supine position Fixes on the target Eyelids gently separated Plunger rests on cornea. Look for movement of the needle Additional weights –if reading is <4 IOP derived from conversion table

Sources of error

Ocular rigidity

High ocular rigidity-high hyperopia,long standing glaucoma,ARMD

Low ocular rigidity –high myopia,osteogenesis imperfecta,miotic therapy,retinal surgeries

Thick cornea-high value

Othertonometers

TONOPEN

GOLDMAN APPLANATION

PERKINS TONOMETER

PNEUMOTONOMETER

Gonioscopy

Goniolens[direct]

Koeppe, layden, barken

Gonioprism

Goldman single mirror, two mirror, three mirror

Zeiss four mirror

Posner four mirror

Normal angle structures

Ciliary body band

Scleral spur Trabecular

meshwork Schwalbe’s line

Ophthalmoscopy Disc

Focal atropy

Concentric atrophy

Deepening of the cup Advanced glaucomatous cupping

Vascular changes

Haemorrhage,baring of vessels, bayonetting

Retinal nerve fiber layer changes

Peripapillary atrophy

Perimetry Kinetic Static Visual fied defects

Paracentral scotoma

Seidel scotoma Arcuate scotoma Double arcuate

scotoma Nasal step

Angle Closure Glaucoma With pupillary

block Without pupillary

block

Diagnosis depends on : Anterior segment

examination Gonioscopy

Risk factors Age Gender Asians, Chinese, Eskimos Family history Hypermetropia

PathogenesisIncreased opposition between iris and lens

enhance the degree of pupillary block

Increased pressure in posterior chamber

Increased peripheral iris bowing

Iris Bombe

High IOP

Types Latent Subacute Acute congestive Post congestive Chronic Absolute

Acute Congestive Glaucoma

SymptomsSevere pain and vomitingUnilateral visual losscoloured haloesHeadache and vomiting

Signs

Shallow AC Corneal edema Semi dilated pupil High IOP Closed angles

Treatment

Immediately 2% Pilocarpine Steroid eye drops Β blockers Analgesics and antiemetics Lie in supine position I.V. Mannitol + Oral T. Diamox

Treatment

MEDICAL

AFTER CORNEA CLEARS

LASER PI

IF NOT POSSIBLE

TRABECULECTOMY

Cont.d… After 1 hr:

Pilocarpine 2% Yag PI

After 11/2 hr: If IOP is still high 50% oral glycerol 20% Mannitol (1-2g/kg) I.V. over

45minutes

Laser Iridotomy

Clear corneas Less than 1800 of

angle by PAS Surgery:

Trabeculectomy

Congenital Glaucoma

1:10,000 births 65% are boys Pathogenesis:Maldevelopment

of the angle of anterior chamber

Classification

Congenital Glaucoma

Infantile Glaucoma

Juvenile Glaucoma

Clinical Features

Corneal edema Buphthalmos Breaks in DM Optic disc cupping

Diagnosis

Increased IOP Increased Corneal diameter > 11mm at 1yr

> 13mm Treatment:

Goniotomy Trabeculotomy trabeculectomy

Lens related Glaucomas

Phacolytic:

Hyper mature cataract

Corneal edema AC reaction –

psuedo hypopyon Open angles

Treatment

Anti glaucoma drugs

Topical antibiotic steroids

surgery

Phacomorphic Galucoma

Intumscent cataractous lens

Shallow anterior chamber

Treatment: Antiglaucoma drugs Laser iridotomy surgery

Neo vascular Glaucoma

Retinal ischaemia

NVI NVA

OPEN ANGLE ANGLE CLOSURE

Causes Ischeamic CRVO Diabetes Mellitus Miscellaneous

Carotid disease Intra ocular tumor Long standing RD

Symptoms & Signs

Decreased visual acuity Congestion of Globe Very high IOP and corneal edema Severe pain Aqueous flare NVI Gonioscopy - NVA

Treatment

Medical – topical Atropine & steroids Retinal ablation / - DIODE CPC Surgery:

Trab with MMC Aqueous drainage shunts

Retrobulbar alcohol injection Enucleation

Treatment Modalities in glaucoma

MedicalLaserSurgery – Trabeculectomy

combined surgery

Anti Glaucoma Drugs Β blockers

Decreases IOP by decreasing aqueous secretion

Contra indications: Congestive cardiac

failure Heart block Bradycardia Bronchial asthma

Side effects

Iotim, Nyolol, Glucomol 0.5% bd Ocular Systemic

allergy Bradycardia, Hypotention

SPK’s Broncho spasm

tear secretion Hallucination, head ache

nausea, dizziness

Alpha 2 Agonists Brimonidine,

apraclonidine Mechanism:

Decreases aqueous secretion

Increases uveo scleral outflow

Side Effects: Allergic

conjunctiviti s Xerostomia Drowsiness and

headache

PROSTAGLANDIN ANALOGUES

Mechanism Decreases IOP by

increasing uveoscleral outflow

Latanoprost F2 α analogue.005%

Travoprost 0.004% Bimatorpost 0.3% Unoprostone 0.15%

BD

Side Effects Conjunctival hypereamia Eye lash growth and hyperpigmentation of

periorbital skin Anterior uveitis Cystoid macular edema

MIOTICS

Pilocarpine 1% 2% 3% 4% QID Parasympathomimetic stimulates

muscarinic receptors in sphincter pupillae & ciliary body

In POAG – increases aqueous outflow In PACG – opens the angles

Side Effects

Miosis Browache Myopic shift Visual field defect

Carbonic Anhydrase Inhibitors

Inhibits aqueous secretion

Topical CAI Dorzolamide (Trusopt) Brinzolamide (Azopt)

Systemic CAI Acetazolamide

250mg BD

Side Effect

Parasthesia Malaise GI upset Renal Stone Blood dyscrasias

Hyper Osmotic Agents

Glycerol 1g / kg in 50% solution Mannitol 1-2g/kg in 20% solution Side Effects:

Cardiac or renal failure Urinary retention Head ache, nausea

Lasers in Glaucoma

Laser Iridotomy: Indications:

PACG Occludable angles SACG with pupillary block Combined mechanism glaucoma

Laser PI

prerequisites Instil 1% Apraclonidine Miotic pupil Laser settings 4-8 mJ Post laser steroid eye

drops Abraham lens

Complications

Bleeding Iritis Corneal burn Glare Diplopia

Surgery Trabeculectomy:

A conventional filtering procedure creates a new channel for aqueous outflow between the anterior chamber and subtenons space without the use of an artificial device

Partial thickness Full thickness

Management of coexistent cataract and glaucoma

Complications

Wound leak Excessive filteration Pupillary block Malignant glaucoma Hypotony Choroidal detachment

Failing bleb

SIGNS• Injection• Vascularisation• Thickening• Localization• High domed Bleb• Normal / High IOP• Low IOP

Initial few weeks critical

Failing filtration

Frame work for Classification

• IOP

• Bleb

Failing filter – High IOP

Low localized Bleb

External - Subconjunctival fibrosis

- Tight scleral flap sutures

Internal - Sclerectomy obstruction

Failing filter – High IOP

High domed bleb – encapsulated bleb or Tenon’s cyst

Failing filter - Low IOP

Low bleb - Bleb leakElevated diffuse bleb - Over

Filtration hypotony

Bleb Failure

Argon laser suturolysis 0.2sec 50µ 500-700mw

Digital massage Topical steroids 5FU injection DF Nd yag laser Needling of tenons cyst

REFRACTORY GLAUCOMA

AQUEOUS DRAINAGE IMPLANTS

Refractory glaucomas

Cyclo destructive procedures

New diagnostic and surgical procedures

Central corneal thickness assessment

OPTICAL COHERENCE TOMOGRAPHY

ULTRASOUND BIOMICROSCOPY